Rhodiumkatalysierte Polyhydroformylierung mehrfach ungesättigter Fettstoffe - Verlustfreie Katalysatorrezirkulation durch ein neuartiges homogen-heterogen-Verfahren

Eine verlustfreie Katalysatorrezirkulation gelingt bei der Polyhydroformylierung von mehrfach ungesättigten Fettstoffen durch Verwenduing eines in Methanol und Wasser gleich gut löslichen, im Reaktionsprodukt aber völlig unlöslichen Rhodiumcarbonyl-Komplexkatalysatorsystems: Die Hydroformylierung von beispielsweise Linolensäuremethylester kann dann homogen katalysiert in methanolischer Lösung mit hohen Ausbeuten an der gewünschten Triformylverbindung ausgeführt werden. Nach der Reaktion wird das Methanol abdestilliert, der ausfallende Katalysatorkomplex in Wasser aufgenommen und vom Reaktionsprodukt abgetrennt. Eine Abtrennung des Katalysators durch Filtration ist ebenfalls möglich. Nach dem Abdampfen des Wassers wird das Katalysatorsystem wieder in Methanol aufgenommen und ohne Aktivitätsverlust in den Prozeß zurückgeführt. Vor allem das Lithiumsalz der Triphenylphosphanmonosulfonsäre bildet als Komplexligand für das Rhodiumcarbonyl ein Katalysatorsystem mit dem gewünschten Löslichkeitsverhalten für die homogen-heterogen-Technologie der Hydroformylierung höhermolekularer Olefine, wie beispielsweise der mehrfach ungesättigten Fettstoffe. Rhodium-catalyzed polyhydroformylation of multiple unsaturated fatty substances - catalyst recycling without waste by a novel homogeneous-heterogeneous procedure. A catalyst recycling in the polyhydroformylation of multiple unsaturated fatty compounds without waste is enabled by the use of rhodiumcarbonyl complex catalyst systems which are easily soluble in methanol and water but completely insoluble in the reaction product: The hydroformylation of, e.g. linolenic acid methylester, is performed homogeneously catalyzed in a methanolic solution with high yields. After the reaction, methanol is distilled off, the precipitated catalyst system is dissolved in water and separated from the hydroformylation products. It is also possible to separate the precipitated catalyst system by a filtration procedure. After evaporation of the water the catalyst system is redissolved in methanol and returned into the process without any loss of catalyst activity. Especially rhodiumcarbonyl complex catalyst systems with the lithium salt of triphenylphosphine-monosulfonic acid as complex ligand have a suitable solution behaviour for the novel homogeneous-heterogeneous technology in the hydroformylation of higher molecular olefins, e.g. multiple unsaturated fatty substances.     

Hydroformylation of unsaturated fatty acids

When hydroformylation of unsaturated fatty materials is done with rhodium-triphenyl phosphine (or phosphite) catalysts, a number of advantages become apparent compared to cobalt carbonyl-catalyzed reactions. With rhodium, the reaction can be carried out (a) at pressures as low as 200 psi, (b) at each double bond location in a polyunsaturated fatty acid, and (c) in high yield and conversion. Solubilized catalyst can be recovered from distillation residue and readsorbed on spent catalyst support by thermal treatment in a rotary kiln. The reconstituted catalyst is more active than the original catalyst and can be recycled indefinitely at a relatively low cost. Recently developed supports for “homogeneous” catalysis may make catalyst recovery even more effective. Acetalation, oxidation with air to polycarboxylic acids and catalytic hydrogenation to hydroxymethyl compounds can be done easily and in high yield on mono-, di- and triformyl derivatives alike. Other reactions investigated for monoformyl fatty esters include reductive amination to form aminomethyl derivatives and Tollen’s condensation with formaldehyde to form geminal,bis-hydroxymethyl compounds. although the Northern Center has carried out some basic investigations on the hydroformylation reaction and on the chemistry of the hydroformylated products, there is a great deal more that can be done with regard to synthesis of new compounds and development of new applications.     

Catalytic hydroformylation and hydrocarboxylation of unsaturated fatty compounds

The two catalyst systems rhodium-triphenylphosphine and palladium chloride-triphenylphosphine were investigated for the respective hydroformylation and hydrocarboxylation of oleic acid or ester to produce C-19 bifunctional compounds. Compared to conventional cobalt carbonyl for making formylstearate, rhodium-triphenylphosphine permits lower pressures (1000–2000 psi vs. 3000–4000 psi), higher conversions (95% vs. 80%), and no loss of functionality (vs. 15% hydrogenation with cobalt). Although palladium chloride-triphenylphosphine for hydrocarboxylation introduces the carboxyl function directly into the fatty acid chain, CO pressures of 3000–4000 psi and corrosion-resistant equipment are necessary. When applied to polyunsaturated fatty acids, both rhodium and palladium catalyst systems have the outstanding advantage of introducing functionality at each double bond position to produce polyformyl- and polycarboxystearates. Selected formyl derivatives were converted in excellent yield to acetals, to acids and their esters, to hydroxymethyl compounds and their esters, and also to aminomethyl compounds that could be condensed to polyamides. Several of the esters and acetals were effective primary plasticizers for poly(vinyl chloride) that had outstanding low volatility characteristics. Other applications for these new and highly versatile derivatives included rigid urethane foams, urethane-modified coatings, ester lubricants, and a shrink-resist treatment for wool.     

Catalytic hydroformylation of unsaturated fatty derivatives with cobalt carbonyl

Two cobalt-carbonyl oxo processes were developed to prepare useful products in high yield from fatty derivatives. In one process, hydroformylation in the presence of MeOH at 120 C gives dimethyl acetal esters from either methyl oleate or oleic acid. In the other, a two-step process, hydroformylation (120 C) followed by hydrogenation (180 C) gives better yields of hydroxymethyl esters from both mono- and polyunsaturated fatty substrates. Recycling the cobalt catalyst was demonstrated for the second process. The acetal and acetoxymethyl derivatives of the oxo products have utility as polyvinyl chloride plasticizers.     

Acyl esters from oxo-derived hydroxymethylstearates as plasticizers for polyvinyl chloride

Hydroxymethylstearates were made by hydroformylation or oxo reaction of mono- and polyunsaturated fats and esters with either rhodium-triphenylphosphine or cobalt carbonyl catalysts. Rhodium-oxo products were hydrogenated with nickel catalyst, whereas, cobalt-oxo products were heated directly under hydrogen pressure. Hydroxymethyl fatty alcohols also were prepared by a two-step copper-chromite hydrogenation of hydroformylated linseed fatty esters. Of these hydroxymethyl compounds, 39 were converted to their acetates and other acyloxy derivatives and then evaluated as primary plasticizers for polyvinylchloride. For compounds with good compatibility, methyl 9(10)-acetoxymethylstearate and 9(10)-acetoxymethyloctadecyl acetate gave the lowest flex temperature (−47 C). An unusual combination of good compatibility and low flex temperature was obtained with 2-methoxyethyl 9(10)-acetoxymethylstearate. Addition of more than one acetoxymethyl group in the fatty acid molecule, made possible by rhodium hydroformylation, imparted good compatibility and outstanding permanence (low migration and volatility) but raised flex temperature. Butyl diacetoxymethylstearate, methyl triacetoxymethylstearate, and polyacetoxymethyloctadecyl acetate from linseed esters displayed good compatibility, strength, and volatility characteristics. As glycerides, acetoxymethylated safflower and linseed oils produced good compatibility and outstanding permanence, better than esters commonly used as commercial plasticizers.     

Extraction of a Homogeneous Rhodium Catalyst from Saturated Branched Fatty Derivatives

Saturated branched fatty derivatives are of great interest for the lubricants and cosmetics industry due to their improved temperature and viscosity behavior compared to the corresponding linear homologues. One way to produce saturated branched derivatives is the homogeneous rhodium‐catalyzed conjugation and co‐oligomerization of linoleic compounds based on renewable resources, e.g., sunflower oil, with ethene. The catalyst extraction behavior of the homogeneous rhodium catalyst RhCl₃·3H₂O from saturated branched fatty derivatives for catalyst recycling was studied. Investigation of the extraction parameters was performed using the model substance isostearic acid. Additionally, extraction of rhodium from co‐oligomer mixtures with different grade of saturation was carried out successfully. Also, the influence of solvent residues from prior reaction steps was evaluated.     

水溶性铑-膦络合物催化烯烃氢甲酰化反应--阳离子表面活性剂的加速作用

介绍了以水溶性铑-膦络合物RhCl(CO)(TPPTS)₂作为催化剂前体在水/有机两相体系中催化烯烃氢甲酰化反应研究的进展,阐述了阳离子表面活性剂的加速作用和介稳态胶束-离子对协同作用机理关系.通过两相体系中界面分子组装和选择与烯烃分子链长相匹配的表面活性剂, 设计制备了高区域选择性复合催化剂体系.当采用双长链表面活性剂与铑-膦络合物组成的复合催化体系时,在不搅拌的情况下就显示出极高的催化活性.     

Mizellare Zweiphasen-Hydroformylierung von ungesättigten Fettstoffen mit wasserlöslichen Rhodiumcarbonyl/tert. Phosphan-Komplexkatalysatorsystemen

Micellar Two Phase-Hydroformylation of Multiple Unsaturated Fatty Substances with Water Soluble Rhodiumdicarbonyl/tert. Phosphine Catalyst Systems Low- and medium-molecular ω-unsaturated carboxylic acid methyl esters inclusive of the ω-decenoic acid ester can be hydrofomylated successfully according to the two phase method in an aqueous-organic medium using the water soluble rhodium carbonyl/tris(sodium-m-sulfonatophenyl)phosphine complex as catalyst system. Highermolecular unsaturated fatty acid esters, e.g. the triple unsaturated linolenic acid methyl ester or fatty oils like linseed oil can be hydroformylated only according to the micellar two phase technique in course of which surfactant micelles cause a solubilisation of the water insoluble unsaturated fatty substances in the aqueous catalyst phase. The different efficiences of the various types of surfactants for the micellar two phase hydroformylation was investigated and interpreted. Best suitable for the micellar two-phase hydroformylation are cationic surfactants. By means of these surfactants linolenic acid methyl ester could be hydroformylated to the triformyl derivative with a selectivity of 55%. The recovery of the catalyst solution free from losses of rhodium succeeded by simple phase separation in a technically satisfying manner.     

Development of a continuous process for the hydroformylation of long-chain olefins in aqueous multiphase systems

The challenging task of homogeneous catalysis is the efficient combination of reaction and catalyst recycling. In the hydroformylation of long-chain olefins generally cobalt-based catalysts are used, but in our investigation we used rhodium-based catalysts, because of their higher activity in comparison to cobalt catalysts. In hydroformylation reactions, the recycling of the expensive rhodium catalyst as well as the selectivity to linear aldehydes are very challenging. Multiphase systems offer the possibility to increase the interfacial area during reaction on the one hand and to separate the metal–ligand complexes easily from the organic product phase after reaction, to recycle the expensive catalyst for further reactions, on the other hand. Solubilisers such as surfactants or polar solvents can be used to formulate such a tuneable solvent system. Upon cooling of the reaction mixture, phase separation is achieved. Based on that combination of reaction and phase separation for catalyst recycling, a novel process concept was developed for the hydroformylation of long-chain olefins. In order to show the applicability of that concept in a continuous process a fully automated miniplant was designed.     

Polyether triaryl phosphine oxides for hydroformylation of oleyl alcohol in micellar catalysis

Water-soluble triaryl phosphine oxides bearing polyether moiety proved to be efficient ligand for rhodium catalyzed aqueous/organic two-phase hydroformylation of water-immiscible oleyl alcohol. Under the selected conditions, yield of aldehydes reached 83.3% with 70 h⁻¹ of TOF. The in situ formed catalyst was easily separated from the reaction mixture and could be employed in the successive reaction runs. It was observed that the catalyst exhibited high activity in the isomerization of oleyl alcohol during the hydroformylation. As a result, 19% of hydroformylation product was determined to be 18-formyl-octaldecyl-1-ol.     

New phosphorus self-assembling ligands for the tandem hydroformylation–Wittig olefination reaction of homoallylic alcohols — A key step for stereoselective pyran synthesis

New self-assembled phosphorus ligands are synthesized and used in the rhodium complex catalyzed hydroformylation–Wittig reaction of homoallylic olefins under optimized condition. A subsequent oxa-Michael intramolecular reaction yields β-pyran derivatives (conversion and diastereoselectivity up to 99%).     

Verlustfreie Katalysatorrezirkulation durch ein neuartiges Verfahrensprinzip bei der Hydroformylierung höhermolekularer Olefine

Free-of-loss Catalyst Recycling in the Hydroformylation of Higher Molecular Olefins by a Novel Process Technology In this paper a novel homogenous-heterogeneous procedure for the hydroformylation reaction of higher molecular olefins is presented, at which the reaction itself is homogeneously catalyzed and only after the reaction the catalyst complex is heterogenized only for separation. This procedure is achieved by using the lithium salt of triphenylphosphine monosulfonic acid (Li-TPPMS) as complex ligand for the hydroformylation catalyst and methanol as solubilizer. Li-TPPMS and its complexes with metal carbonyls are highly soluble in water and methanol, but completely insoluble in almost all other organic solvents. After the reaction the methanol is distilled off. The catalyst system becomes insoluble and can be separated from the reaction product by filtration or by extraction with water. The aqueous catalyst solution is evaporated to dryness and the catalyst system dissolved in methanol for a new reaction.     

Acetale als neuartige Kraftstoffadditive aus Glycerin und Olefinen

Long chain olefins are converted into aldehydes by hydroformylation using synthesis gas CO/H₂ and further converted in an acid‐catalyzed conversion with glycerol in a one‐pot procedure. Yields are up to 95 %. The obtained mixtures of 5‐ and 6‐membered rings are potential fuel additives offering alternative use of glycerol from renewable resources. By optimization of reaction conditions such as catalyst precursor, ligand, pressure, temperature, solvent or catalyst/substrate ratio a highly selective hydroformylation towards linear acetals was achieved. For synthesis of larger amounts, glycerol was converted with alkenes on a 2‐L‐scale and with aldehydes on a 60‐L‐scale.     

Hydroformylation of 1-hexene in supercritical carbon dioxide using a heterogeneous rhodium catalyst. 1. Effect of process parameters

The hydroformylation of 1-hexene in supercritical carbon dioxide is catalyzed with a heterogeneous rhodium catalyst that is active, selective, and stable for the formation of heptanal. The aldehyde yield and regioselectivity can be affected through changes in catalyst support structure, CO₂ solvent pressure, and reaction temperature. A complex reaction pathway model is described that allows determination of rate constants, which are in turn, evaluated as a function of temperature and pressure. Analysis reveals an activation volume of −474 cm³/mol and activation energy of 31.9 kJ/mol for the hydroformylation pathways.     

Synthetic Applications of Synergism using Catalytic Binuclear Elimination Reactions. Further Examples of Rhodium‐Manganese and Rhodium‐Rhenium‐Catalyzed Hydroformylations

Synergism has been previously observed in both rhodium‐manganese‐ and rhodium‐rhenium‐catalyzed hydroformylation. Furthermore, detailed in situ spectroscopic investigations have conclusively shown that the phenomenological origin of this synergistic effect is catalytic binuclear elimination (J. Am. Chem. Soc. 2003 , 125, 5540–5548; 2007 , 129, 13327–13334). In the present contribution, further substrates are used in the hydroformylation reaction with both rhodium‐manganese and rhodium‐rhenium. In situ spectroscopic studies show that (i) significant rate enhancements occur in the mixed metal systems with the new substrates and (ii) the organometallics present in the active systems, and their concentration profiles are consistent with those present in the previously studied catalytic binuclear elimination reactions (CBER). It is therefore concluded that catalytic binuclear elimination is a rather general mechanism in mixed metal hydroformylations and is rather independent of the substrates used. Further discussion is given to mechanistic aspects, synthetic efficiency, and the possibility that such synergistic effects might be useful to other classes of organic syntheses.     

Biphasic and Flow Systems Involving Water or Supercritical Fluids

Two processes are described for improving reaction rates for relatively hydrophobic substrates in aqueous biphasic systems. In the first, 1-octyl-3-methylimidazolium bromide ([Octmim]Br) increases the rate of hydroformylation of 1-octene from 8% conversion in 24 h to full conversion of 1.5 h. Phase separation is fast and catalyst retention is good. 1-Hexyl-3-methylimidazolium bromide gives little rate enhancement, whilst 1-decyl-3-methylimidazolium bromide gives stable emulsions., The mechanism of action of these additives is discussed. In the second approach, functionalising PPh₃ with amidine groups allows the rhodium catalysed hydroformylation of 1-octene in toluene with a very high reaction rate. The catalyst can be switched between toluene and water by bubbling CO₂ and back into toluene by bubbling N₂ at 60 °C. This switching has been used to separate the catalyst from hydrophobic (from 1-octene) or hydrophilic (from allyl alcohol) aldehydes obtained from hydroformylation reactions. CO₂ expanded liquids have been shown to be effective media for transporting substrates and catalysts over supported ionic liquid phase (SILP) catalysts. The advantages offered over all gas phase and liquid phase catalysts are discussed.     

Heterogenized HRh(CO)(PPh3)3 on zeolite Y using phosphotungstic acid as tethering agent: a novel hydroformylation catalyst

Heterogenization of HRh(CO)(PPh₃)₃ tethered through phosphotungstic acid to zeolite Y support, gives a novel hydroformylation catalyst with excellent stability, reusability and even improved activity. The activity, selectivity and stability of this catalyst for hydroformylation of a variety of linear and branched olefinic substrates have been demonstrated. The heterogenized HRh(CO)(PPh₃)₃ catalyst was recycled several times without loss of any activity. The catalyst was characterized by powder XRD, SEM, XPS, and ³¹P CP MAS NMR to establish true heterogeneity and morphological characteristics.     

Core-Functionalized Dendrimeric Mono- and Diphosphine Rhodium Complexes; Application in Hydroformylation and Hydrogenation

Three novel series of core-functionalized dendrimeric phosphine ligands were synthesized and their rhodium complexes were studied as catalysts in both hydroformylation and hydrogenation of alkenes. Generally similar activities were obtained for the dendrimeric systems and the parent compounds except in the hydroformylation of a bulky substrate, 4,4,4-triphenylbut-1-ene, which gave a significant decrease in activity when the larger dendrimers were used. The rhodium complexes of the dppf-type dendrimeric ligands were studied in the hydrogenation of dimethyl itaconate in a continuous-flow membrane reactor showing a reasonable constant formation of the product compared to the non-dendrimeric catalyst.     

双环戊二烯在水溶性铑膦络合催化体系中的氢甲酰化反应

研究了采用水溶性铑膦络合催化体系对双环戊二烯的氢甲酰化反应，考查了反应温度、相转移剂ＣＴＡＢ、铑催化剂浓度等对反应的影响。氢甲酰化反应的产物经ＧＣ／ＭＳ鉴定是不饱和的三环癸单醛     

Biodiesel from rapeseed oil,methanol and KOH. 3. Analysis of composition of actual reaction mixture

Detailed analysis is described of the samples taken after suitable reaction times from the actual reaction mixture during the production of biodiesel fuel using methanolysis of rapeseed oil catalyzed by KOH. Three methods for stoppage of reaction (neutralisation of catalyst, dilution by two suitable solvents) in the sample are used. The contents of mono‐, di‐ and triacylglycerols, methylesters of fatty acids (biodiesel) and potassium salts of fatty acids of rapeseed oil, glycerol (by HPLC method), basicity (by potentiometric titration) and water (by GC and Karl‐Fischer method) in the samples are determined. An example of these determinations is described.